Seiko Watch Prospex Alpinist Mens SPB123J1. Seiko Prospex challenges every limit, with a collection of timepieces for sports lovers and adventure seekers whether in the water, in the sky or on land. Since launching Japans first divers watch in 1965, Seikos innovative technology has changed global standards. Seiko watches are constantly striving to bring ever greater reliability and safety to both professional and recreational divers.